<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>多行交叉轴对齐</title>
    <style>
        .box {
            background-color: lightgreen;
            /* 多行交叉轴使用的前提：
             1.要有换行
             2.在交叉轴方向有空余的空间可以移动*/
            display: flex;
            flex-wrap: wrap;
            width: 700px;
            height:350px;
            align-content: space-between; /* 交叉轴两端对齐 */
            align-content: space-around; /* 交叉轴环绕对齐 */
            align-content: space-evenly; /* 交叉轴公平对齐 */
            align-content: center; /*交叉轴居中对齐*/
            align-content: flex-start; /* 交叉轴起点对齐 */
            align-content: flex-end; /*交叉轴终点对齐*/
        }
        .item {
            width: 120px;
            height: 130px;
            border: 2px solid red;
            font-size: 30px;
        }
    </style>
</head>
<body>
<div class="box">
    <div class="item">1</div>
    <div class="item">2</div>
    <div class="item">3</div>
    <div class="item">4</div>
    <div class="item">5</div>
    <div class="item">6</div>
    <div class="item">7</div>
    <div class="item">8</div>
    <div class="item">9</div>
</div>
</body>
</html>